1. Field of the Invention
The invention relates to an expanding plug comprising an expanding sleeve provided at least over a part of its length with at least one slot, an expanding screw arranged in the expanding sleeve concentrically to a common central longitudinal axis and supporting with a head on a rim of the expanding sleeve against the latter, and an expanding cone held in an untwistable manner with respect to the expanding sleeve and axially displaceable in the latter on a plug-in end of the expanding sleeve located opposite the rim, which expanding cone comprises an internal thread for taking up an external thread of the expanding screw and an expanding section for expanding the region of the expanding sleeve associated to the plug-in end when pulling this expanding section into the expanding sleeve by means of the expanding screw, which is bent from steel sheet and which comprises edge surfaces of its wall limiting a joint gap, which edge surfaces extend in the direction of the central longitudinal axis and tangentially to the latter bear against each other.
2. Background Art
In an expanding plug of this type known from U.S. Pat. No. 5,112,174 the expanding cone is bent from metal sheet. The edges of its wall limiting a joint gap are positively connected with each other by means of a dovetailed locking in the direction of the central longitudinal axis and tangentially to the latter. This embodiment features the principal advantage that the expanding cone is of comparably little volume compared with the usual massive expanding cones of zinc die casting. This means that it is of low weight. Steel is considerably cheaper than zinc, so that it is cost-effective. Furthermore, the solidity of steel is considerably higher than that of zinc. The manufacturing of the positive locking, however, is combined with some manufacturing expenditure.